JP2811743B2 - Optical memory - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an optical storage device used for audio equipment, computer peripheral equipment, and the like.

(Prior Art) In recent years, a compact disk (hereinafter, abbreviated as CD), which is one of optical storage media, has been widely used. As an applied technology of this CD, CD-ROM which recorded computer data on CD
Are increasingly popular, and there is a demand for a storage medium having high storage stability under high temperature and high humidity.

(Problems to be Solved by the Invention) Conventionally, in an optical memory, a reflection film made of aluminum, gold, or the like is formed on a base body made of glass, polycarbonate resin, or the like, and a protective film such as a resin is formed on the reflection film. Are coated. When such a conventional optical storage medium is placed in a high-temperature, high-humidity environment, corrosion occurs when the reflection film material is aluminum, and peels off from the base body when the reflection film material is gold. When the reflection film changes in this way, the error rate, which is an index for signal reading, increases, and there is a problem that the above-mentioned needs cannot be met.

The present invention has been made in view of the conventional circumstances as described above, and by improving the adhesion of the gold reflective film to the base body while maintaining the excellent corrosion resistance of the gold reflective film. It is another object of the present invention to provide an optical memory body having improved weather resistance.

(Means for Solving the Problems) According to the present invention, in a read-only optical memory having a reflectance of 70% or more, the content of a base, gold and at least tantalum coated on the base exceeds 0 atomic%. An optical storage element comprising a reflection film containing up to 25 atomic% and not containing rhenium. The reason why the content of tantalum is limited is that a reflectance of 70%, which is a standard of CD, is secured within this range.

 The optical memory of the present invention is manufactured, for example, as follows.

First, as the base body, for example, a glass obtained by coating a silicon oxide, a titanium oxide, a silicon nitride, or the like on a tempered glass, a quartz glass, a glass coated with a sol-gel film, a polyolefin resin,
Acrylic resin, fluorine resin, polycarbonate resin and the like are used.

Next, a high-frequency magnetron sputtering method, an ion plating method, a plasma CVD method, a vacuum deposition method, etc., on the base body, as a reflective film, a material containing gold and at least tantalum in an amount of more than 0 atomic% and not more than 25 atomic%. To a thickness of 10 to 500 nm.

Further, if necessary, a protective film made of various oxides, nitrides, resins, or the like is formed on the reflective film, thereby obtaining the optical memory of the present invention.

(Action) Gold and at least tantalum exceed 0 atomic% and 25 atomic%
The reflection film included in the film has strong adhesion to the base body and the protective film, and also has excellent corrosion resistance. For this reason, the reflective film does not peel off from the base body or the protective film does not peel off from the reflective film, so that an optical memory having high reliability can be obtained.

(Example) Hereinafter, the present invention will be described in detail with reference to tables and drawings.

A reflective film having the composition shown in Table 1 was formed on a base body made of the material shown in Table 1 by sputtering to a thickness shown in Table 1 respectively. Next, a protective film made of the material shown in Table 1 was formed on the reflective film to produce five optical storage media.

FIG. 1 is a partial cross-sectional view showing one embodiment of the optical storage body manufactured as described above. In the figure, 1 is a base body, 2 is a reflective film, and 3 is a protective film.

Next, these samples, conventional product A using aluminum as a reflective film, and conventional product B using gold as a reflective film have a temperature of 80 ° C.
An environmental resistance test at 90 ° C. and a relative humidity of 90% was performed for one month, and an error rate as an index of signal quality was measured. Table 2 shows the results.

As shown in Table 2, the error rate of each sample is 5 × 10 ⁻⁵ at the initial stage, but after one month of the environmental resistance test, the error rate of the sample of the present invention is slightly deteriorated. However, it was so good that it could not be compared with the conventional product.

(Effects of the Invention) As described above in detail, the optical storage element of the present invention is formed by forming a material containing at least tantalum in gold at more than 0 atomic% and up to 25 atomic% as a reflective film. The adhesion between the substrate and the base body and the adhesion between the reflection film and the protective film are improved, and the corrosion resistance is excellent, and the reliability is much higher than that of the conventional product.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing one embodiment of the optical storage body of the present invention. 1 ... underlying body, 2 ... reflective film, 3 ... protective film.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 7/24 C23C 24/00-30/00 C23C 14/00-14/58 C23C 16/00-16 / 56

Claims (1)

(57) [Claims] 1. A read-only optical memory having a reflectance of 70% or more, comprising a base, gold and at least tantalum coated on the base in an amount exceeding 0 atomic% and not more than 25 atomic%, and rhenium. An optical memory, comprising a reflection film containing no.